Organic light-emitting diodes (OLEDs) find ever-increasing applications in display and lighting technology. Crucial components of OLEDs are special molecules termed emitters. Present emitters for the blue range of the visible spectrum have some shortcomings compared to their green and red counterparts. Our approach to improve blue emitters is summarized in a recent contribution to q&more.

01.07.2019 - Tracing the Solvent Uptake of a Polymer by FSRM

The penetration of polymers by solvents has implications for diverse fields, such as the packaging of liquids and drug delivery. In experimental studies of this uptake processes, one aims at the spatial distribution of the solvent as a function of time. In a recent joint study with the group of Stefan Egelhaaf, we demonstrate that femtosecond stimulated Raman microscopy (FSRM) - developed in house - is a very suitable technique for this purpose. Read more in 10.1021/acs.macromol.9b00205

19.02.2019 - On the Large Apparent Stokes Shift of Phthalimides

Phthalimides are electron deficient aromatics. They often serve as acceptors in donor acceptor conjugates for photo induced electron transfer. Surprisingly, the photo-physics of this important chromophore has not been studied in detail yet. Here, in a collaborative effort involving groups from Cologne (Axel Griesbeck) and Düsseldorf (Peter Gilch and Oliver Weingart), the response of the phthalimide chromophore on photo-excitation was scrutinized by time resolved spectroscopy and quantum chemistry. Based on the results, the large Stokes shift of phthalimides and their solvent dependent fluorescence decay can be explained. Read more in 10.1039/C8CP07795A.

12.07.2018 - Poster Award for Anna Reiffers

Early July 2018 photochemists from all over the world (41 countries) gathered in Dublin for the biannual PhotoIUPAC conference. We are very proud that out of 220 contributions Anna Reiffers’ poster on “The Emissive State of Phthalimides” was selected for the poster award.

Congrats to Anna!

24.05.2018 - Imaging & Microscopy

In 2007 our group introduced a new technique for non-linear Raman imaging – femtosecond stimulated Raman microscopy, FSRM for short. With this technique it is now possible to record a complete Raman spectrum in only 100 µs which in turn allows for faster imaging. More information about this technique as well as its current applications can be found in a recently published article in the journal “Imaging & Microscopy”.

02.03.2018 - An Intuitive Demonstration of First Order Kinetics for the Lecture Hall

Many time dependent phenomena like radioactive decays and a plethora of chemical reactions obey first order kinetics. It is, thus, part of all chemistry and physics curricula. An intuitive introduction to the topic is described in our recent contribution for the Journal of Chemical Education. The lecture hall demonstration outlined therein relies on capillary flow and digital data acquisition. With a simple set-up a first order process can literally be seen. Read more in L. Festersen, P. Gilch, A. Reiffers, R. Mundt, J. Chem. Educ. (2018).

19.02.2018 - Scholarship for Janina Diekmann

Our PhD student Janina Diekmann was awarded a scholarship by the Jürgen Manchot Stiftung. This institution will support her research on light induced DNA damage for two years.